U.S. patent application number 10/436148 was filed with the patent office on 2004-03-11 for brush saw cutting head with integral herbicide applicator.
Invention is credited to Hobday, Bryan Marc, Williams, Peter.
Application Number | 20040045166 10/436148 |
Document ID | / |
Family ID | 4171205 |
Filed Date | 2004-03-11 |
United States Patent
Application |
20040045166 |
Kind Code |
A1 |
Hobday, Bryan Marc ; et
al. |
March 11, 2004 |
Brush saw cutting head with integral herbicide applicator
Abstract
A chamber is formed in the upper end of a brush saw cutting head
housing. The brush saw cutting element drive spindle's upper end
projects into the chamber. The drive spindle's lower end projects
beneath the housing and is drivingly couplable to the cutting
element. A disc is mounted against the underside of the cutting
element. A cavity is formed in the disc. At least one channel
extends through the disc, between the cavity and the disc's
external rim. An aperture extends through the drive spindle,
between the chamber and the cavity. Herbicide supplied to the
chamber flows from the chamber, through the drive spindle aperture,
into the cavity. The drive spindle rotates the disc. Centrifugal
force imposed on herbicide within the cavity forces the herbicide
through the channel(s) onto the underside of the cutting element,
for transfer onto the stumps of material cut by the element.
Inventors: |
Hobday, Bryan Marc;
(Vancouver, CA) ; Williams, Peter; (Vancouver,
CA) |
Correspondence
Address: |
Oyen Wiggs Green & Mutala
The Station-Suite 480
601 West Cordova Street
Vancouver
BC
V6B 1G1
CA
|
Family ID: |
4171205 |
Appl. No.: |
10/436148 |
Filed: |
May 13, 2003 |
Current U.S.
Class: |
30/123.3 ;
30/276; 47/1.5; 56/16.8 |
Current CPC
Class: |
A01D 43/14 20130101 |
Class at
Publication: |
030/123.3 ;
030/276; 056/016.8; 047/001.5 |
International
Class: |
B26B 001/00; B25F
003/00; B26B 003/00; B26B 011/00; B26B 007/00; A01D 019/00; A01C
001/00; A01G 001/00 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 11, 2002 |
CA |
2400315 |
Claims
What is claimed is:
1. A brush saw cutting head, comprising: (a) a drive spindle having
a lower end drivingly couplable to a cutting element; (b) an
aperture extending through said drive spindle between an upper end
of said drive spindle and a lower region of said drive spindle
above said drive spindle lower end; (c) a member positioned against
an underside of said cutting element; and, (d) at least one fluid
flow channel extending through said member in fluid communication
between said drive spindle aperture and an external rim of said
member.
2. A brush saw cutting head as defined in claim 1, wherein said
member further comprises a disc having a cavity, said cavity in
fluid communication between said drive spindle aperture and said
fluid flow channel.
3. A brush saw cutting head as defined in claim 1, further
comprising a housing having a chamber formed in an upper end of
said housing, said drive spindle upper end projecting into said
chamber, said chamber in fluid communication between said drive
spindle aperture and said chamber.
4. A brush saw cutting head as defined in claim 2, further
comprising a housing having a chamber formed in an upper end of
said housing, said drive spindle upper end projecting into said
chamber for fluid communication between said drive spindle aperture
and said chamber.
5. A brush saw cutting head as defined in claim 4, further
comprising a seal mounted between said chamber and said drive
spindle upper end to prevent fluid passage from said chamber
between said housing and said drive spindle.
6. A brush saw cutting head as defined in claim 5, further
comprising a fluid deflector fixed to said drive spindle beneath
said seal, said deflector rotatable with said drive spindle to
deflect fluid outwardly away from said drive spindle.
7. A brush saw cutting head as defined in claim 4, wherein said
drive spindle aperture further comprises: (i) a longitudinal
aperture extending between said chamber and said drive spindle
lower region; and, (ii) a transverse aperture in said drive spindle
lower region, said transverse aperture extending between said
longitudinal aperture and said cavity.
8. A brush saw cutting head as defined in claim 4, further
comprising a fluid flow orifice in said housing, said orifice
extending between said chamber and a socket couplable to one end of
a fluid conduit.
9. A brush saw cutting head as defined in claim 8, further
comprising: (a) a fluid canister couplable to an opposite end of
said fluid conduit; and, (b) a fluid-containing bladder within said
canister, said bladder in fluid communication with said fluid
conduit.
10. A brush saw cutting head as defined in claim 9, further
comprising a valve in said canister for injection of pressurized
air between said canister and said bladder.
11. A brush saw cutting head, comprising: (a) a housing; (b) a
chamber formed in an upper end of said housing; (c) a drive spindle
having an upper end projecting into said chamber and a lower end
projecting beneath said housing, said drive spindle lower end
drivingly couplable to a cutting element; (d) a seal mounted
between said chamber and said drive spindle upper end to prevent
fluid passage from said chamber between said housing and said drive
spindle; (e) a disc mounted against an underside of said cutting
element; (f) a cavity formed in said disc; (g) at least one channel
extending through said disc between said cavity and an external rim
of said disc; and, (h) an aperture extending through said drive
spindle between said chamber and said cavity.
12. A method of applying herbicide to the underside of a brush saw
cutting element while said cutting element is drivingly rotated by
a drive spindle, said method comprising: (a) passing said herbicide
through said drive spindle into a fluid flow channel formed
adjacent said underside of said brush saw cutting element; and, (b)
passing said herbicide through said fluid flow channel onto said
underside of said brush saw cutting element.
13. A method as defined in claim 12, further comprising sealing
said drive spindle to prevent herbicide passage externally along
said drive spindle.
14. A brush saw cutting head, comprising: (a) a drive spindle
having a lower end drivingly couplable to a cutting element; (b) an
aperture extending through said drive spindle between an upper end
of said drive spindle and a lower region of said drive spindle
above said drive spindle lower end; (c) a member positioned against
an underside of said cutting element; and, (d) at least one fluid
flow channel extending over said member in fluid communication
between said drive spindle aperture and an external rim of said
member.
15. A brush saw cutting head as defined in claim 14, wherein said
member further comprises a disc having a cavity, said cavity in
fluid communication between said drive spindle aperture and said
fluid flow channel.
16. A brush saw cutting head as defined in claim 14, further
comprising a housing having a chamber formed in an upper end of
said housing, said drive spindle upper end projecting into said
chamber, said chamber in fluid communication between said drive
spindle aperture and said chamber.
17. A brush saw cutting head as defined in claim 15, further
comprising a housing having a chamber formed in an upper end of
said housing, said drive spindle upper end projecting into said
chamber for fluid communication between said drive spindle aperture
and said chamber.
18. A brush saw cutting head as defined in claim 17, further
comprising a seal mounted between said chamber and said drive
spindle upper end to prevent fluid passage from said chamber
between said housing and said drive spindle.
19. A brush saw cutting head as defined in claim 18, further
comprising a fluid deflector fixed to said drive spindle beneath
said seal, said deflector rotatable with said drive spindle to
deflect fluid outwardly away from said drive spindle.
20. A brush saw cutting head as defined in claim 17, wherein said
drive spindle aperture further comprises: (i) a longitudinal
aperture extending between said chamber and said drive spindle
lower region; and, (ii) a transverse aperture in said drive spindle
lower region, said transverse aperture extending between said
longitudinal aperture and said cavity.
21. A brush saw cutting head as defined in claim 17, further
comprising a fluid flow orifice in said housing, said orifice
extending between said chamber and a socket couplable to one end of
a fluid conduit.
22. A brush saw cutting head as defined in claim 21, further
comprising: (a) a fluid canister couplable to an opposite end of
said fluid conduit; and, (b) a fluid-containing bladder within said
canister, said bladder in fluid communication with said fluid
conduit.
23. A brush saw cutting head as defined in claim 22, further
comprising a valve in said canister for injection of pressurized
air between said canister and said bladder.
Description
TECHNICAL FIELD
[0001] This invention pertains to controlled application of
herbicide to the underside of a brush saw's saw blade to prevent
resprouting of cut brush.
BACKGROUND
[0002] Brush saws (sometimes called brushcutters) are used to cut
brush or other vegetation from power line right of way areas,
roadsides, forestry plantations, etc. In a typical brush saw, a
drive motor and a cutting head are mounted at opposite ends of a
support tube. A drive shaft is drivingly coupled through the
support tube, between the drive motor and a pinion gear mechanism
inside the cutting head. The pinion gear mechanism is in turn
coupled to a drive gear spindle on which a cutting element such as
a saw blade is rotatably mounted. Handlebars are provided on the
support tube, between the drive motor and the cutter head. An
operator grasps the handlebars and manipulates the brush saw to
move the rotating saw blade through brush or other plant material
which is to be cut. Controls on the handlebar enable the operator
to stop the motor, vary the motor's speed, etc.
[0003] A commonly encountered problem is that stumps of cut plant
material tend to resprout fresh shoots or buds which eventually
mature, necessitating repetition of the cutting operation.
Herbicide can be applied to the stumps to kill the cut plant or
significantly retard its ability to resprout. It is often desirable
to apply herbicide simultaneously with the cutting operation to
avoid the time and expense of a separate herbicide application
operation; and, because herbicides are more effective if applied
immediately after cutting.
[0004] One relatively unsuccessful prior art technique is to
dispense (drip) herbicide from a reservoir onto the upper surface
of the brush saw's rotating saw blade. The difficulty with this
technique is that little, if any, herbicide reaches the underside
of the saw blade. Consequently, little, if any, herbicide is
transferred to the cut material stumps, which is where the
herbicide is required to prevent resprouting.
[0005] In another prior art technique, a herbicide reservoir is
mounted on the underside of the brush saw's saw blade. Centrifugal
force imposed on the reservoir as it rotates with the saw blade
forces herbicide upwardly from the reservoir through a gasket onto
the underside of the saw blade. Although this technique applies
herbicide where it is needed (i.e. on the underside of the saw
blade where the herbicide can be transferred to cut stumps) the
somewhat bulky reservoir reduces the saw blade's effective cutting
area. This technique also does not allow the operator to monitor or
continually control the rate at which herbicide is dispensed while
the brush saw is operating. Moreover, despite the reservoir's bulk,
it contains a limited amount of herbicide. This necessitates more
frequent stoppage of the brush saw so that the reservoir can be
refilled, thus increasing the risk of herbicide spillage.
[0006] This invention addresses the shortcomings of the prior
art.
BRIEF DESCRIPTION OF DRAWINGS
[0007] FIG. 1 is an exploded side elevation view of a brush saw
cutting head in accordance with the invention.
[0008] FIG. 2 is a side elevation view of the FIG. 1 apparatus in
the assembled state.
[0009] FIG. 3 is a top plan view of the FIG. 2 apparatus.
[0010] FIG. 4 is an enlarged cross-sectional view of the FIG. 2
apparatus.
[0011] FIG. 5 is a cross-sectional side elevation view of a
herbicide canister for use with the apparatus of FIGS. 1-4.
DESCRIPTION
[0012] Throughout the following description, specific details are
set forth in order to provide a more thorough understanding of the
invention. However, the invention may be practiced without these
particulars. In other instances, well known elements have not been
shown or described in detail to avoid unnecessarily obscuring the
invention. Accordingly, the specification and drawings are to be
regarded in an illustrative, rather than a restrictive, sense.
[0013] As seen in FIG. 1, the invention provides a brush saw
cutting head housing 10 having an upwardly and rearwardly
projecting socket 12 into which a brush saw support tube (not
shown) can be fitted in conventional fashion. One end of the brush
saw's drive shaft (not shown) is coupled to spiral bevel (pinion)
gear 14 which is rotatably mounted within bearing 16 inside socket
12. Snap rings 18, 20 prevent dislodgement of pinion gear 14 and
bearing 16 from socket 12. Optional spacer 22 maintains spacing
between pinion gear 14 and bearing 16. Grease insert 24 assists
lubrication.
[0014] The teeth of pinion gear 14 mesh with those of spiral bevel
(spindle) gear 26 which is mounted inside a vertically chambered
portion of housing 10. Drive spindle 28 extends through and is
fixed to spindle gear 26, for rotation therewith. Bearings 30, 32
rotatably support drive spindle 28 within housing 10. Shim 34
maintains snug fit engagement of bearing 32 once snap ring 36 is in
place on the opposite side of bearing 32. Snap ring 36 also
prevents dislodgement of spindle gear 26, drive spindle 28 and
bearings 30, 32 from within housing 10.
[0015] A second socket 40 projects upwardly and rearwardly from
housing 10, above socket 12. As seen in FIG. 4, a fluid flow
orifice 42 extends between socket 40 and chamber 44 formed in the
upper end of housing 10. The upper end of drive spindle 28
protrudes into chamber 44. The lower end of drive spindle 28
projects beneath housing 10. Chamber 44 is closed by screwing
threaded cap 46 into mating threads machined in the upper end of
chamber 44. Cap 46 can be unscrewed and removed from housing 10 to
provide maintenance access to chamber 44. This allows O-ring 48,
deflector 50, snap ring 52, seal backing disc 54, seal 56 and snap
ring 58 to be fitted over the upper end of drive spindle 28, as
seen in FIG. 4. Seal 56 prevents fluid leakage downwardly from
chamber 44, between housing 10 and drive spindle 28. Deflector 50
rotates with drive spindle 28 to deflect outwardly away from drive
spindle 28 any fluid which may seep past seal 56 if seal 56 fails,
to protect gears 14, 26 and bearings 16, 30, 32 from damage due to
contact with herbicide. O-ring 60 provides sealing engagement when
cap 46 is screwed onto housing 10 as aforesaid.
[0016] Spindle washer 62 is fitted over the lower end of drive
spindle 28, which protrudes vertically downwardly from the lower
end of housing 10. Saw blade 64 is then fitted over protrusion 66
on the underside of spindle washer 62. Reservoir disc 68 is held
against the underside of saw blade 64 by lock nut 70. Reservoir
disc 68's shallow depth and small diameter minimizes reduction of
saw blade 64's effective cutting area. Optional seal 72 can be
mounted between reservoir disc 68 and lock nut 70 to prevent fluid
leakage downwardly past reservoir disc 68. In operation, the brush
saw's drive motor (not shown) rotates the drive shaft (not shown),
drivingly rotating meshed gears 14, 26 thereby drivingly rotating
drive spindle 28, saw blade 64 and reservoir disc 68.
[0017] Herbicide supplied from a suitable container such as
canister 74 (FIG. 5) is controllably dispensed through flexible
conduit 76, one end of which is fitted over coupler 78 mounted in
the canister 74's removable cap 79. A flexible bladder 80 within
canister 74 contains the herbicide fluid. One-way air valve 82
mounted in cap 79 allows compressed air to be injected into space
84 between canister 74's inner surface and bladder 80's outer
surface. Air pressure within space 84 collapses bladder 80 as
herbicide is dispensed therefrom through orifice 86, coupler 78 and
conduit 76, allowing herbicide to flow out of bladder 80
irrespective of canister 74's orientation.
[0018] The opposite end of conduit 76 is fitted within socket 40.
Suitable coupling and metering devices (not shown) can be provided
in conduit 76 to allow the operator to control the volume and flow
rate of herbicide dispensed from bladder 80 through conduit 76 and
orifice 42 into chamber 44. Quick connect-disconnect type coupling
devices (not shown) can be used to allow the operator to rapidly
disconnect an empty canister and connect a full canister in its
place, with minimal herbicide spillage. Empty canisters can be
efficiently refilled at a centralized location where potential
herbicide spillage can be dealt with quickly and effectively.
[0019] A longitudinal aperture 90 is bored axially through drive
spindle 28 from the upper end of drive spindle 28. Aperture 90
extends only to the lower region of drive spindle 28--not
completely through drive spindle 28. A second aperture 92 is bored
transversely through drive spindle 28 to intersect aperture 90.
Aperture 92 is located such that when the apparatus is assembled as
shown in FIG. 4, aperture 92 also intersects cavity 94 formed in
the upper portion of reservoir disc 68. This allows herbicide to
flow from chamber 44 through apertures 90, 92 into cavity 94
adjacent the underside of saw blade 64.
[0020] At least one and preferably a plurality of small diameter
fluid flow channels 96 are formed in and extend radially outwardly
through the upper end of reservoir disc 68, between cavity 94 and
the external rim of reservoir disc 68. As saw blade 64 and
reservoir disc 68 rotate, centrifugal force is imposed on the
herbicide within cavity 94, forcing the herbicide through
channel(s) 96 onto the underside of saw blade 64 for transfer onto
the stumps of material by saw blade 64.
[0021] A weep hole 98 (FIG. 3) bored in housing 10 permits
herbicide to escape from the space between deflector 50 and seal 56
in the event of failure of seal 56.
[0022] As will be apparent to those skilled in the art in the light
of the foregoing disclosure, many alterations and modifications are
possible in the practice of this invention without departing from
the spirit or scope thereof. For example, neither reservoir disc 68
nor cavity 94 are essential and may both be eliminated. In such
case, fluid flow channel(s) 96 can be provided in the upper end of
lock nut 70 such that herbicide flows directly from aperture 92
into fluid flow channel(s) 96. Alternatively, fluid flow channel(s)
96 can be provided in seal 72, if seal 72 is used. As a further
alternative, if reservoir disc 68 is provided, it need not have a
cavity 94--fluid flow channel(s) 96 may extend through the upper
end of reservoir disc 68 and intersect aperture 92 without any
intermediate cavity.
[0023] As another example, seal 56 is shown in the drawings as a
VARILIP.TM. lip type seal, but it may alternatively be an inline
type seal such as a ceramic seal (not shown) mounted atop drive
spindle 28 to allow fluid to flow directly from fluid flow orifice
42, through the inline seal and into aperture 90. If an inline seal
is used then chamber 44 can be eliminated--space need only be
provided to contain the inline seal.
[0024] As a further example, chamber 44 need not be formed within
housing 10 as illustrated. A separate external chamber (with or
without a cap) can be mounted atop, above or beside housing 10. In
such case, second socket 40 could be configured to allow fluid flow
orifice 42 to communicate with the external chamber, and a separate
coupler conduit (not shown) provided to allow fluid to flow from
the external chamber into aperture 90, with appropriate sealing
again being provided to protect gears 14, 26 and bearings 16, 30,
32 from damage due to contact with herbicide.
[0025] The scope of the invention is to be construed in accordance
with the substance defined by the following claims.
* * * * *